#include<iostream>
using namespace std;
#include<string>
void test()
{
	string s1 = "abcdef";
	for (int i = 0; i < s1.size(); i++)
	{
		cout << s1[i] << " ";
	}cout << endl;
	for (int i = 0; i < s1.size(); i++)
	{
		cout << s1.at(i) << " ";
	}cout << endl;

for (int i = 0; i < s1.size(); i++)
{
	s1.at(i) = '1';
	cout << s1.at(i) << " ";
}cout << endl;
}

int main()
{
	test();
}
